Transfer (liquidate and invest in their name) must happen before 31st March 2018. Also, it is beneficial if your parents income and future gain from this investment falls below basic exemption limit (you may include additional Rs.1,00,000 tax-free LTCG income also). Otherwise, it is of no use. Also, you have to mention the ways of how you transferred and reasons like GIFT or WHAT? If it is through gift, then make sure the gift agreement should be there in place to avoid future tax complications.